#include <stdio.h>
extern int do_auth(void);
enum {BUFFERSIZE=24};
void report_error(const char *msg){
    const char *error_log;
    char buffer[BUFFERSIZE];
    sprintf(buffer,"Error:%s",error_log);
    printf("%s\n",buffer);
}
int main(void){
    if(do_auth()==-1){
        report_error("Unable to login");
    }
    return 0;
}